Until recently, fasting was something done for religious reasons or in a desperate attempt to lose weight. No more. A red hot new trend called intermittent fasting is creating a deafening buzz in fitness and health circles around the world.
But is intermittent fasting safe? Is it really the holy grail of fat loss it’s made out to be?
Intermittent Fasting 101
It’s crucial to make a distinction between simply starving yourself to fit into a tuxedo before your best friend’s wedding and the regimented and scientifically-based intermittent fasting. There are many ways to intermittent fast, but the most popular way is known as alternate day fasting where you simply chow down for a 24-hour stretch and fast for the next 24. Typically, “fasting” means no food, only water. However, some variations of the system allow minimal caloric intake (500 calories or less) on fasting days.
The Theory Behind Intermittent Fasting
Imagine yourself not in front of your computer screen, but in a blazing hot savannah. Your local Subway restaurant is gone and in its place it a pack of gazelles. The scene that you’re imagining is the eating environment for humans for most of our specie’s existence. Without a reliable food source, fasting was the norm.
However, in today’s food-abundant world, we only fast by choice. Considering our brains are hardwired to eat as much as possible, it’s a choice we rarely make. But emerging science is suggesting that our genes are designed for fasting. And by constantly eating, we never tap into their full fat-burning potential.
Intermittent Fasting Science
Before the year 2000, there had been limited research on intermittent fasting as a way to help extremely obese people lose weight. Not surprisingly, taking away half of their meals resulted in rapid and dramatic weight loss. Because the effects of intermittent fasting were so obvious, they didn’t raise any eyebrows in nutrition circles.
Then, a research team at the Pennington Biomedical Research Center in Baton Rouge made a startling discovery. The scientists wanted to see the biological effects of intermittent fasting on healthy people that weren’t obese. In 2005, they recruited 16 healthy young volunteers to live inside their lab for 22 days. Over that 12-day period, the volunteers alternated between gorging and fasting – alternate day fasting.
In research published in the “American Journal of Clinical Nutrition” the researchers noted their results. Although the volunteers were already lean, they lost a jaw-dropping 4% of their body fat in just over 3 weeks. Not surprisingly, the researcher’s analysis found that their fat burning capabilities skyrocketed since the start of the study.
Interestingly, none of the fasting volunteers lost an appreciable amount of muscle mass.
And another study, this one conducted by University of Illinois scientists, investigated the effects of alternate day fasting in overweight subjects over 8 weeks. Not only did the subjects lose significant amounts of weight but they slashed off 2.5 inches from their waistline! Even more remarkably, the average amount of body fat lost was more than 12 lbs. It’s important to note that we’re not talking about 12 lbs. of weight loss, but 12 lbs. of fat loss. The researchers also noted that, “…fat-free mass [muscle-mass] did not change.”
While the research is still in its infancy, it appears that intermittent fasting is a great way to shed body fat without losing precious muscle mass.